Pixel and organic light emitting display using the same

ABSTRACT

A pixel includes an organic light emitting diode, a first driver and a second driver. The second driver controls an amount of current supplied from a first power source to the organic light emitting diode, corresponding to a previous data signal. The first driver stores a current data signal supplied from a data line and supplies the previous data signal to the second driver. In the pixel, the second driver includes a sixth transistor coupled between an initialization power source and a first node coupled to a gate electrode of a first transistor, the sixth transistor being configured to turn on when a first control signal is supplied; and a seventh transistor coupled between the first power source and a second node commonly coupled to the first and second drivers, the seventh transistor being configured to turn on when the first control signal is supplied.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Korean PatentApplication Nos. 10-2013-0005453 and 10-2013-0005454, both filed on Jan.17, 2013, and Korean Patent Application No. 10-2013-0075336 filed onJun. 28, 2013, in the Korean Intellectual Property Office, the entirecontents of all three of which are incorporated herein by reference intheir entirety.

BACKGROUND

1. Field

Embodiments of the present invention relate to a pixel and an organiclight emitting display using the same.

2. Description of the Related Art

With the recent advances in information technologies, the importance ofa display as a mode of presenting information has increased.Accordingly, flat panel displays (FPDs) such as a liquid crystal display(LCD), an organic light emitting display and a plasma display panel(PDP) are being increasingly used.

An organic light emitting display displays images using organic lightemitting diodes that emit light through recombination of electrons andholes. The organic light emitting display has a fast response speed andhas low power consumption.

SUMMARY

Embodiments of the present invention provide a pixel and an organiclight emitting display using the same, which can be driven at a lowfrequency.

Embodiments of the present invention also provide a pixel and an organiclight emitting display using the same, which can improve display qualityby compensating for degradation of an organic light emitting diode.

According to an embodiment of the present invention, there is provided apixel including: an organic light emitting diode; a second driverconfigured to control an amount of current supplied from a first powersource to the organic light emitting diode, corresponding to a previousdata signal; and a first driver configured to store a current datasignal supplied from a data line and supply the previous data signal tothe second driver, wherein the second driver includes: a sixthtransistor coupled between an initialization power source and a firstnode coupled to a gate electrode of a first transistor, the sixthtransistor being configured to turn on when a first control signal issupplied; and a seventh transistor coupled between the first powersource and a second node commonly coupled to the first and seconddrivers, the seventh transistor being configured to turn on when thefirst control signal is supplied.

The initialization power source may be set to a voltage lower than thedata signal supplied to the data line.

The first driver may include a second transistor coupled between thedata line and a third node, the second transistor being configured toturn on when a scan signal is supplied to a scan line; a thirdtransistor coupled between the third and second nodes, the thirdtransistor being configured to turn on when a second control signal issupplied; and a second capacitor coupled between the third node and theinitialization power source.

The third and sixth transistors may have turn-on periods not overlappedwith each other.

The second transistor may have a turn-on period not overlapped withthose of the third and sixth transistors.

The second driver may include an eighth transistor coupled between thefirst power source and the second node coupled to a first electrode ofthe first transistor, the eighth transistor being configured to turn offwhen an emission control signal is supplied and to turn on otherwise; afifth transistor coupled between the first node and a second electrodeof the first transistor, the fifth transistor being configured to turnon when the second control signal is supplied; a ninth transistorcoupled between the second electrode of the first transistor and ananode electrode of the organic light emitting diode, the ninthtransistor being configured to turn off when the emission control signalis supplied and to turn on otherwise; and a first capacitor coupledbetween the first node and the first power source.

The eighth transistor may have a turn-on period not overlapped withthose of the fifth and sixth transistors.

The fifth and sixth transistors may have turn-on periods not overlappedwith each other.

The second driver may further include a fourth transistor coupledbetween the anode electrode of the organic light emitting diode and theinitialization power source, the fourth transistor being configured toturn on when the first control signal is supplied.

The second driver may further include a fourth transistor coupledbetween the anode electrode of the organic light emitting diode and theinitialization power source, the fourth transistor being configured toturn on when the second control signal is supplied.

The second driver may further include a fourth transistor positionedbetween the anode electrode of the organic light emitting diode and asecond control line to which the second control signal is supplied, thefourth transistor having a gate electrode coupled to the second controlline.

The second driver may further include a photodiode coupled in parallelto the first capacitor between the first node and the first powersource.

The photodiode may control the increment of the voltage at the firstnode, corresponding to the luminance of the organic light emittingdiode.

The photodiode may control the increment of the voltage at the firstnode, in proportion to the luminance of the organic light emittingdiode.

The second driver may further include a third capacitor coupled betweenthe anode electrode of the organic light emitting diode and the secondnode.

According to an embodiment of the present invention, there is providedan organic light emitting display, including: a control driverconfigured to supply a first control signal to a first control line, andto supply a second control signal to a second control line during afirst period in one frame; a scan driver configured to supply anemission control line to an emission control line during the firstperiod, a second period and a third period in the one frame, andprogressively supply a scan signal to scan lines during a fourth periodin the one frame; a data driver configured to supply a data signal todata lines, in synchronization with the scan signal, during the fourthperiod in the one frame; and pixels positioned in an area defined by thescan lines and the data lines, the pixels storing a current data signalduring a period in which the pixels emit light, corresponding to aprevious data signal.

The previous data signal may be a data signal supplied in a previousframe, and the current data signal may be a data signal supplied in acurrent frame.

The scan driver may concurrently supply a scan signal to the scan linesduring the third period.

The data driver may supply a reset voltage to the data lines during thethird period.

The reset voltage may be set to a voltage in a voltage range of the datasignal.

Each pixel may control an amount of current flowing from a first powersource to a second power source via an organic light emitting diode,corresponding to the previous data signal.

The first power source may be set to a first voltage during the fourthperiod, and may be set to a second voltage different from the firstvoltage during the first to third periods.

The second voltage may be a voltage lower than the first voltage.

Each pixel may include an organic light emitting diode; a second driverconfigured according to an amount of current supplied from the firstpower source to the organic light emitting diode, corresponding to theprevious data signal; and a first driver configured to store the currentdata signal, and to supply the previous data signal to the seconddriver.

The first driver may include a second transistor coupled between acorresponding one of the data lines and a third node, the secondtransistor being configured to turn on when a scan signal is supplied toa corresponding one of the scan lines; a third transistor coupledbetween the third node and a second node commonly coupled to the firstand second drivers, the third transistor being configured to turn onwhen the second control signal is supplied; and a second capacitorcoupled between the third node and an initialization power source.

The second driver may include a first transistor configured to have afirst electrode coupled to the first power source via the second nodecommonly coupled to the first and second drivers, the first transistorhaving a gate electrode coupled to a first node; a fifth transistorcoupled between a second electrode of the first transistor and the firstnode, the fifth transistor being configured to turn on when the secondcontrol signal is supplied; a sixth transistor coupled between the firstnode and the initialization power source, the sixth transistor beingconfigured to turn on when the first control signal is supplied; aseventh transistor coupled between the second node and the first powersource, the seventh transistor being configured to turn on when thefirst control signal is supplied; an eighth transistor coupled betweenthe second node and the first power source, the eighth transistor beingconfigured to turn off when the emission control signal is supplied andto turn on otherwise; and a ninth transistor coupled between the secondelectrode of the first transistor and an anode electrode of the organiclight emitting diode, the ninth transistor being configured to turn offwhen the emission control signal is supplied and to turn on otherwise.

The initialization power source may be set to a voltage lower than thedata signal.

The second driver may further include a fourth transistor coupledbetween the anode electrode of the organic light emitting diode and theinitialization power source, the fourth transistor being configured toturn on when the first control signal is supplied.

The second driver may further include a fourth transistor coupledbetween the anode electrode of the organic light emitting diode and theinitialization power source, the fourth transistor being configured toturn on when the second control signal is supplied.

The second driver may further include a fourth transistor positionedbetween the anode electrode of the organic light emitting diode and thesecond control line, the fourth transistor having a gate electrodecoupled to the second control line.

The second driver may further include a photodiode coupled in parallelwith the first capacitor between the first node and the first powersource.

The photodiode may control the increment of the voltage at the firstnode, corresponding to the luminance of the organic light emittingdiode.

According to an embodiment of the present invention, there is provided apixel including an organic light emitting diode; a second driverconfigured to control an amount of current supplied from a first powersource to the organic light emitting diode, corresponding to a previousdata signal; and a first driver configured to store a current datasignal supplied from a data line and to supply the previous data signalto the second driver, wherein the second driver comprises: a fourthtransistor coupled between an anode electrode of the organic lightemitting diode and an initialization power source, the fourth transistorbeing configured to turn on when a first control signal is supplied; anda seventh transistor coupled between the first power source and a secondnode commonly coupled to the first and second drivers, the seventhtransistor being configured to turn on when the first control signal issupplied.

The first driver may further include a second transistor coupled betweenthe data line and a third node, the second transistor being configuredto turn on when a scan signal is supplied to a scan line; a thirdtransistor coupled between the third and second nodes, the thirdtransistor being configured to turn on when a second control signal issupplied; and a second capacitor coupled between the third node and theinitialization power source.

The second driver may further include a fifth transistor coupled betweena first node coupled to a gate electrode of a first transistor and asecond electrode of the first transistor, the fifth transistor beingconfigured to turn on when a second control signal is supplied; a sixthtransistor coupled between the initialization power source and the firstnode, the sixth transistor being configured to turn on when the firstcontrol signal is supplied; an eighth transistor coupled between thefirst power source and the second node, the second node being coupled toa first electrode of the first transistor, the eighth transistor beingconfigured to turn off when an emission control signal is supplied andto turn on otherwise; a ninth transistor coupled between the secondelectrode of the first transistor and the anode electrode of the organiclight emitting diode, the ninth transistor being configured to turn offwhen the emission control signal is supplied and to turn on otherwise;and a first capacitor coupled between the first node and the first powersource.

The eighth transistor may have a turn-on period not overlapped withthose of the fifth and sixth transistors.

The fifth and sixth transistors may have turn-on periods not overlappedwith each other.

The photodiode may control the increment of the voltage at the firstnode, in proportion to the luminance of the organic light emittingdiode.

The second driver may further include a third capacitor coupled betweenthe anode electrode of the organic light emitting diode and the secondnode.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the example embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.Like reference numerals refer to like elements throughout.

FIG. 1 is a diagram illustrating an organic light emitting displayaccording to an embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a pixel according to a firstembodiment of the present invention.

FIG. 3 is a waveform diagram illustrating a driving method according toan embodiment of the present invention.

FIG. 4 is a waveform diagram illustrating a driving method according toanother embodiment of the present invention.

FIG. 5 is a waveform diagram illustrating a driving method according tostill another embodiment of the present invention.

FIG. 6 is a diagram illustrating an embodiment of a driving frequency in3D driving.

FIG. 7 is a circuit diagram illustrating a pixel according to a secondembodiment of the present invention.

FIG. 8 is a circuit diagram illustrating a pixel according to a thirdembodiment of the present invention.

FIG. 9 is a graph illustrating the increment of the voltage at a firstnode, corresponding to degradation of an organic light emitting diode.

FIG. 10 is a circuit diagram illustrating a pixel according to a fourthembodiment of the present invention.

FIG. 11 is a circuit diagram illustrating a pixel according to a fifthembodiment of the present invention.

FIG. 12 is a circuit diagram illustrating a pixel according to a sixthembodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, certain exemplary embodiments according to the presentinvention will be described with reference to the accompanying drawings.Here, when a first element is described as being coupled to a secondelement, the first element may be directly coupled to the second elementor may be indirectly coupled to the second element via a third element.Further, some of the elements that are not essential to the completeunderstanding of the invention are omitted for clarity. Also, likereference numerals refer to like elements throughout.

FIG. 1 is a diagram illustrating an organic light emitting displayaccording to an embodiment of the present invention.

Referring to FIG. 1, the organic light emitting display according tothis embodiment includes pixels positioned in an area defined by scanlines S1 to Sn and data lines D1 to Dm, a display unit 140 including thepixels 142, a scan driver 110 for driving the scan lines S1 to Sn and anemission control line E, a control driver 120 for driving first andsecond control lines CL1 and CL2, a data driver 130 for driving the datalines D1 to Dm, and a timing controller 150 for controlling the scandriver 110, the control driver 120 and the data driver 130.

The scan driver 110 supplies a scan signal to the scan lines S1 to Sn.For example, the scan driver 110, as shown in FIG. 3, may progressivelysupply the scan signal to the scan lines S1 to Sn during a fourth periodT4 in one frame 1F. The scan driver 110, as shown in FIG. 4, mayconcurrently (e.g., simultaneously) supply the scan signal to the scanlines S1 to Sn during a third period T3 in the one frame 1F.

The scan driver 110 supplies an emission control signal to the emissioncontrol line E commonly coupled to the pixels 142. For example, the scandriver 110 may supply the emission control signal to the emissioncontrol line E during the other periods T1, T2 and T3 except the fourthperiod T4 in the one frame 1F. Here, the scan signal supplied from thescan driver 110 is set to a voltage (e.g., a low voltage) at whichtransistors included in the pixels 142 are turned on, and the emissioncontrol signal is set to a voltage (e.g., a high voltage) at which thetransistors are turned off.

The control driver 120 supplies a first control signal to the firstcontrol line CL1 commonly coupled to the pixels 142, and supplies asecond control signal to the second control line CL2 commonly coupled tothe pixels 142. Here, the first and second control signals CL1 and CL2are not overlapped with each other. For example, the control driver 120supplies the first control signal to the first control line CL1 during afirst period T1 in the one frame 1F, and supplies the second controlsignal to the second control line CL2 during a second period T2 in theone frame 1F. Here, the first and second control signals are set to avoltage (e.g., a low voltage) at which the transistors can be turned on.

The data driver 130 supplies a data signal to the data lines D1 to Dm soin synchronization with the scan signal supplied to the scan lines S1 toSn during the fourth period T4 in the one frame 1F. Here, the datadriver 130 may alternately supply left and right data signals everyframe for the purpose of 3D driving. Additionally, the data driver 130may supply a reset voltage Vr to the data lines D1 to Dm during thethird period T3 in the one frame 1F. Here, the reset voltage Vr may beset to a voltage in a voltage range of the data signal.

The timing controller 150 controls the scan driver 110, the controldriver 120 and the data driver 130, corresponding to a synchronizationsignal supplied from the outside of the organic light emitting display.

The display unit 140 includes the pixels 142 positioned in the areadefined by the scan lines S1 to Sn and the data lines D1 to Dm. Thepixels 142, during the fourth period T4, charge a data signal (currentdata signal) of a current frame and concurrently (e.g., simultaneously)emit light corresponding to a data signal (e.g., a previous data signal)of a previous frame. To this end, the pixels 142, during the fourthperiod T4, control an amount of current flowing from a first powersource ELVDD to a second power source ELVSS via organic light emittingdiodes.

Although it has been illustrated in FIG. 1 that, for convenience ofillustration, the emission control line E is coupled to the scan driver110, and the control lines CL1 and CL2 are coupled to the control driver120, the present invention is not limited thereto. In practice, theemission control line E and the control lines CL1 and CL2 may be coupledto various drivers. For example, the emission control line E and thecontrol lines CL1 and CL2 may be commonly coupled to the scan driver110.

FIG. 2 is a circuit diagram illustrating a pixel according to a firstembodiment of the present invention. For convenience of illustration, apixel coupled to an m-th data line Dm and an n-th scan line Sn will beshown in FIG. 2.

Referring to FIG. 2, the pixel 142 according to this embodiment includesan organic light emitting diode OLED and a pixel circuit 144 thatcontrols an amount of current supplied to the organic light emittingdiode OLED.

An anode electrode of the organic light emitting diode OLED is coupledto the pixel circuit 144, and a cathode electrode of the organic lightemitting diode OLED is coupled to the second power source ELVSS. Theorganic light emitting diode OLED generates light (e.g., light having apredetermined luminance) corresponding to an amount of current suppliedfrom the pixel circuit 144. The second power source ELVSS is set to avoltage lower than that of the first power source ELVDD so that acurrent can flow through the organic light emitting diode OLED.

The pixel circuit 144 includes a first driver 146 for storing thecurrent data signal, and a second driver 148 for controlling an amountof the current supplied to the organic light emitting diode OLED,corresponding to the previous data signal.

The first driver 146 stores the current data signal supplied from thedata line Dm and concurrently (e.g., simultaneously) supplies theprevious data signal stored in the previous frame to the second driver148. To this end, the first driver 146 includes a second transistor M2,a third transistor M3 and a second capacitor C2.

A first electrode of the second transistor M2 is coupled to the dataline Dm, and a second electrode of the second transistor M2 is coupledto a third node N3. A gate electrode of the second transistor M2 iscoupled to the scan line Sn. The second transistor M2 is turned on whenthe scan signal is supplied to the scan line Sn, to supply the datasignal from the data line Dm to the third node N3.

A first electrode of the third transistor M3 is coupled to the thirdnode N3, and a second electrode of the third transistor M3 is coupled tothe second driver 148 (e.g., at a second node N2). A gate electrode ofthe third transistor M3 is coupled to the second control line CL2. Thethird transistor M3 is turned on when the second control signal issupplied to the second control line CL2, to allow the third and secondnodes N3 and N2 to be electrically coupled to each other.

The second capacitor C2 is coupled between the third node N3 and a fixedvoltage source (e.g., an initialization power source Vint). The secondcapacitor C2 charges a voltage corresponding to the current data signalduring a period in which the second transistor M2 is turned on.

The second driver 148 charges a voltage corresponding to the previousdata signal supplied from the first driver 146, and controls an amountof current flowing from the first power source ELVDD to the second powersource ELVSS via the organic light emitting diode OLED, corresponding tothe charged voltage. To this end, the second driver 148 includes a firsttransistor M1, fourth to ninth transistors M4 to M9, and a firstcapacitor C1.

A first electrode of the first transistor (e.g., a driving transistor)M1 is coupled to the second node N2, and a second electrode of the firsttransistor M1 is coupled to a fourth node N4. A gate electrode of thefirst transistor M1 is coupled to a first node N1. The first transistorM1 controls an amount of current supplied to the organic light emittingdiode OLED, corresponding to a voltage applied to the first node N1.

A first electrode of the fourth transistor M4 is coupled to the anodeelectrode of the organic light emitting diode OLED, and a secondelectrode of the fourth transistor M4 is coupled to the initializationpower source Vint. A gate electrode of the fourth transistor M4 iscoupled to the first control line CL1. The fourth transistor M4 isturned on when the first control signal is supplied to the first controlline CL1, to supply the voltage of the initialization power source Vintto the anode electrode of the organic, light emitting diode OLED. Here,the initialization power source Vint is set to a voltage lower than thedata signal. For example, the initialization power source Vint may beset to a voltage lower than that obtained by subtracting the absolutethreshold voltage of the first transistor M1 from the data signal havingthe lowest voltage.

A first electrode of the fifth transistor M5 is coupled to the fourthnode N4, and a second electrode of the fifth transistor M5 is coupled tothe first node N1. A gate electrode of the fifth transistor M5 iscoupled to the second control line CL2. The fifth transistor M5 isturned on when the second control signal is supplied to the secondcontrol line CL2, to allow the first and fourth nodes N1 and N4 to beelectrically coupled to each other. When the first and fourth nodes N1to N4 are electrically coupled to each other, the first transistor M1 isdiode-coupled.

A first electrode of the sixth transistor M6 is coupled to the firstnode N1, and a second electrode of the sixth transistor M6 is coupled tothe initialization power source Vint. A gate electrode of the sixthtransistor M6 is coupled to the first control line CL1. The sixthtransistor M6 is turned on when the first control signal is supplied tothe first control line CL1, to supply the voltage of the initializationpower source Vint to the first node N1.

A first electrode of the seventh transistor M7 is coupled to the firstpower source ELVDD, and a second electrode of the seventh transistor M7is coupled to the second node N2. A gate electrode of the seventhtransistor M7 is coupled to the first control line CL1. The seventhtransistor M7 is turned on when the first control signal is supplied tothe first control line CL1, to supply the voltage of the first powersource ELVDD to the second node N2.

A first electrode of the eighth transistor M8 is coupled to the firstpower source ELVDD, and a second electrode of the eighth transistor M8is coupled to the second node N2. A gate electrode of the eighthtransistor M8 is coupled to the emission control line E. The eighthtransistor M8 is turned off when the emission control signal is suppliedto the emission control line E, and is turned on when the emissioncontrol signal is not supplied.

A first electrode of the ninth transistor M9 is coupled to the fourthnode N4, and a second electrode of the ninth transistor M9 is coupled tothe anode electrode of the organic light emitting diode OLED. A gateelectrode of the ninth transistor M9 is coupled to the emission controlline E. The ninth transistor M9 is turned off when the emission controlsignal is supplied to the emission control line E, and is turned on whenthe emission control signal is not supplied.

The first capacitor C1 is coupled between the first power source ELVDDand the first node N1. The first capacitor C1 charges a voltagecorresponding to the previous data signal and the threshold voltage ofthe first transistor M1.

FIG. 3 is a waveform diagram illustrating a driving method according toan embodiment of the present invention.

Referring to FIG. 3, one frame according to this embodiment is dividedinto first to fourth periods T1 to T4.

First, the emission control signal is supplied during the first to thirdperiods T1 to T3, and the emission control signal is not supplied duringthe fourth period T4. When the emission control signal is supplied, theeighth and ninth transistors M8 and M9 are turned off. When the ninthtransistor M9 is turned off, the first transistor M1 and the organiclight emitting diode OLED are electrically decoupled from each other,and accordingly, the organic light emitting diode OLED is set in thenon-emission state during the first to third periods T1 to T3.

The first control signal is supplied to the first control line CL1during the first period T1. When the first control signal is supplied tothe first control line CL1, the fourth, sixth and seventh transistorsM4, M6 and M7 are turned on.

When the fourth transistor M4 is turned on, the voltage of theinitialization power source Vint is supplied to the anode electrode ofthe organic light emitting diode OLED. When the voltage of theinitialization power source Vint is supplied to the anode electrode ofthe organic light emitting diode OLED, the voltage charged in aparasitic capacitor (not shown) equivalently formed in the organic lightemitting diode OLED is discharged.

When the sixth transistor M6 is turned on, the voltage of theinitialization power source Vint is supplied to the first node N1. Whenthe seventh transistor M7 is turned on, the voltage of the first powersource ELVDD is supplied to the second node N2. Here, the initializationpower source Vint is set to a voltage lower than the data signal, andhence the first transistor M1 is set in an on-bias state during thefirst period T1. Then, the first transistor M1 is initialized in theon-bias state, thereby improving display quality.

The second control signal is supplied to the second control line CL2during the second period T2. When the second control signal is suppliedto the second control line CL2, the third and fifth transistors M3 andM5 are turned on. When the fifth transistor M5 is turned on, the firsttransistor M1 is diode-coupled. When the third transistor M3 is turnedon, the voltage of the previous data signal stored in the secondcapacitor C2 is supplied to the second node N2. In this case, thevoltage at the first node N1 is initialized as the voltage of theinitialization power source Vint, lower than the data signal, and hencethe first transistor M1 is turned on.

When the first transistor M1 is turned on, the voltage of the datasignal, applied to the second node N2, is supplied to the first node N1via the diode-coupled first transistor M1. In this case, the firstcapacitor C1 stores a voltage corresponding to the data signal and thethreshold voltage of the first transistor M1.

The supply of the emission control signal to the emission control line Eis maintained during the third period T3.

The supply of the emission control signal to the emission control line Eis stopped during the fourth period T4. When the supply of the emissioncontrol signal to the emission control line E is stopped, the eighth andninth transistors M8 and M9 are turned on. When the eighth transistor M8is turned on, the first power source ELVDD and the second node N2 areelectrically coupled to each other. When the ninth transistor M9 isturned on, the fourth node N4 and the organic light emitting diode OLEDare electrically coupled to each other. Then, the first transistor M1controls an amount of the current flowing from the first power sourceELVDD to the second power source ELVSS via the organic light emittingdiode OLED, corresponding to the voltage applied to the first node N1.In this case, the organic light emitting diode OLED generates light(e.g., light having a predetermined luminance) corresponding to theamount of current supplied thereto.

The scan signal is progressively supplied to the scan lines S1 to Snduring the fourth period T4. When the scan signal is progressivelysupplied to the scan lines S1 to Sn, the second transistor M2 includedin each pixel 142 for each horizontal line is turned on. When the secondtransistor M2 is turned on, the current data signal from a data line(any one of D1 to Dm) is supplied to the third node N3 included in eachpixel 142. In this case, the second capacitor C2 charges a voltagecorresponding to the current data signal. In practice, according toembodiments of the present invention, images are displayed by repeatingthe aforementioned procedure.

FIG. 4 is a waveform diagram illustrating a driving method according toanother embodiment of the present invention. In reference to FIG. 4,detailed descriptions of components that are substantially identical tothose of FIG. 3 will be omitted.

Referring to FIG. 4, during the third period T3 in the driving methodaccording to this embodiment, the scan signal is concurrently (e.g.,simultaneously) supplied to the scan lines S1 to Sn, and the resetvoltage Vr is supplied to the data lines D1 to Dm in synchronizationwith the scan signal.

When the scan signal is supplied to the n-th scan line Sn during thethird period T3, the second transistor M2 is turned on. When the secondtransistor M2 is turned on, the reset voltage Vr is supplied to thethird node N3. That is, the voltage at the third node N3 included ineach pixel 142 is initialized as the reset voltage Vr during the thirdperiod T3.

Subsequently, the scan signal is progressively supplied to the scanlines S1 to Sn during the fourth period T4. When the scan signal issupplied to the n-th scan line Sn, the second transistor M2 is turnedon. When the second transistor M2 is turned on, the current data signalfrom the data line Dm is supplied to the third node N3. In this case,the second capacitor C2 charges a voltage corresponding to the currentdata signal.

Here, the third node N3 is initialized with the reset voltage Vr duringthe third period T3, and hence a uniform voltage corresponding to thecurrent data signal may be charged in the second capacitor C2 during thefourth period T4.

For example, the voltage at the third node N3 included in each pixel 142is set corresponding to the voltage of the previous data signal afterthe second period T2. That is, the voltages at the third nodes N3included in the respective pixels 142 are set different from oneanother, corresponding to the previous data signal. Thus, in a casewhere the voltage at the third node N3 is not initialized, the voltageof the current data signal stored in the second capacitor C2 is alteredby the voltage of the previous data signal, and accordingly, a crosstalkphenomenon may occur.

FIG. 5 is a waveform diagram illustrating a driving method according tostill another embodiment of the present invention. In reference to FIG.5, detailed descriptions of components that are substantially identicalto those of FIG. 4 will be omitted.

Referring to FIG. 5, in the driving method according to this embodiment,the voltage of the first power source ELVDD is changed. That is, thefirst power source ELVDD is set to a first voltage VDD1 during thefourth period T4 in which the pixels 142 emit light, and is set to asecond voltage VDD2 lower than the first voltage VDD1 during the firstto third periods T1 to T3 in which the pixels 142 do not emit light.Here, the second voltage VDD2 is set to a voltage higher than that ofthe initialization power source Vint so that the first transistor M1 isset in the on-bias state during the first period T1.

For example, the first power source ELVDD is set to the second voltageVDD2 during the first to third periods T1 to T3. The voltage of thefirst power source ELVDD is raised to the first voltage VDD1 during thefourth period T4.

When the voltage of the first power source ELVDD is raised to the firstvoltage VDD1 during the fourth period T4, the voltage at the first nodeN1, which is set in a floating state, is also raised. When the voltageat the first node N1 is raised as described above, it is possible toimprove the ability to express (or represent) black.

For example, the first capacitor C1 is charged using the voltage chargedin the second capacitor C2 during the second period T2. In this case,the voltage charged in the first capacitor C1 is set to a voltage lowerthan a desired voltage, and therefore, the organic light emitting diodeOLED emits a small amount of light when the black is expressed (orrepresented). Accordingly, in this embodiment, the voltage of the firstpower source ELVDD and the voltage at the first node N1 correspondingthereto are raised during the fourth period T4, so that it is possibleto prevent the organic light emitting diode OLED from emitting a smallamount of light when the black is expressed (or represented).

FIG. 6 is a diagram illustrating an embodiment of a driving frequency in3D driving.

Referring to FIG. 6, the organic light emitting display according toembodiments of the present invention receives a data signal during anemission period. That is, the pixels 142 store a voltage correspondingto the right (or left) data signal during a period in which an imagecorresponding to the left (or right) data signal. Thus, in embodimentsof the present invention, a 3D image can be implemented at a drivingfrequency of 120 Hz. In FIG. 6, RD represents a right data signal, andLD represents a left data signal. In addition, R represents emissioncorresponding to the right data signal, and L represents emissioncorresponding to the left data signal.

FIG. 7 is a circuit diagram illustrating a pixel according to a secondembodiment of the present invention. In FIG. 7, components that aresubstantially identical to those of FIG. 2 are designated by likereference numerals, and their detailed descriptions will be omitted.

Referring to FIG. 7, the pixel 142 according to this embodiment includesa pixel circuit 200 and the organic light emitting diode OLED.

The pixel circuit 200 includes the first driver 146 for storing thecurrent data signal, and a second driver 202 for controlling an amountof the current supplied to the organic light emitting diode OLED,corresponding to the previous data signal.

The second driver 202 includes a fourth transistor M4′ coupled betweenthe anode electrode of the organic light emitting diode OLED and theinitialization power source Vint. A gate electrode of the fourthtransistor M4′ is coupled to the second control line CL2. The fourthtransistor M4′ is turned on when the second control signal is suppliedto the second control line CL2, to supply the voltage of theinitialization power source Vint to the anode electrode of the organiclight emitting diode OLED. The operating process of the pixel accordingto this embodiment, except the fourth transistor M4′, is substantiallythe same as that of the pixel according to the first embodiment, andtherefore, its detailed description will be omitted.

FIG. 8 is a circuit diagram illustrating a pixel according to a thirdembodiment of the present invention. In FIG. 8, components that aresubstantially identical to those of FIG. 2 are designated by likereference numerals, and their detailed descriptions will be omitted.

Referring to FIG. 8, the pixel 142 according to this embodiment includesa pixel circuit 210 and the organic light emitting diode OLED.

The pixel circuit 210 includes the first driver 146 for storing thecurrent data signal, and a second driver 212 for controlling an amountof the current supplied to the organic light emitting diode OLED,corresponding to the previous data signal.

The second driver 212 includes a photodiode PD coupled in parallel tothe first capacitor C1 between the first power source ELVDD and thefirst node N1. The photodiode PD controls an amount of current suppliedfrom the first power source ELVDD to the first node N1, i.e., thevoltage at the first node N1, corresponding to the brightness of theorganic light emitting diode OLED. In practice, the photodiode PDcontrols the voltage at the first node N1 so that the degradation of theorganic light emitting diode OLED can be compensated for.

The operating process of the pixel will be described. During the fourthperiod T4, the photodiode PD controls an amount of current flowing fromthe first power source ELVDD to the first node N1, i.e., an increment ofthe voltage at the first node N1, in proportion to the luminance of theorganic light emitting diode OLED. In other words, the photodiode PDcontrols the voltage at the first node N1 to be increased as theluminance of the organic light emitting diode OLED increases.

For example, as the organic light emitting diode OLED is degraded, theorganic light emitting diode OLED generates light with a low luminance,corresponding to the same gray level. Thus, the voltage at the firstnode N1 is changed by the photodiode PD, corresponding to thedegradation of the organic light emitting diode OLED. That is, althougha data signal with the same gray level is supplied, an increment of thevoltage at the first node N1 is changed by the photodiode PD.

In a case where the organic light emitting diode OLED emits light,corresponding to a specific gray level j (j is a natural number), theincrement of the voltage at the first node N1 when the organic lightemitting diode OLED is degraded is set lower by a first voltage V1 thanthat of the voltage at the first node N1 when the organic light emittingdiode OLED is not degraded. That is, in the described embodiment of thepresent invention, the increment of the voltage at the first node N1 isset low as the organic light emitting diode OLED is degraded, andaccordingly, it is possible to compensate for a decrease in luminance,caused by the degradation of the organic light emitting diode OLED.

In practice, according to embodiments of the present invention, anamount of current supplied to the organic light emitting diode OLED maybe represented as shown in Equation 1.

$\begin{matrix}{\mspace{79mu}{{I_{oled} = {\frac{1}{2}\mu\; C_{ox}\frac{W}{L}( {{ELVDD} - V_{N\; 1} - {V_{th}}} )^{2}}}{I_{oled} = {\frac{1}{2}\mu\; C_{ox}\frac{W}{L}( {{ELVDD} - \frac{{C\; 2\;{Vdata}} + {C\; 1V\;{int}}}{{C\; 2} + {C\; 1}} - {\Delta\; V_{PD}}} )^{2}}}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

In Equation 1, μ denotes the mobility of the first transistor M1, C_(ox)denotes the gate capacitance of the first transistor, V_(th) denotes thethreshold voltage of the first transistor M1, and W and L denote thechannel width/length ratio of the first transistor M1. In addition,Vdata denotes the voltage of the data signal, and ΔV_(PD) denotes avariation in voltage, caused by the photodiode PD. Referring to Equation1, an amount of the current supplied to the organic light emitting diodeOLED is determined by the voltage of the data signal and the variationin voltage, caused by the photodiode PD. In the variation in voltage,caused by the photodiode PD, an increment of the voltage at the firstnode N1 is set low as the organic light emitting diode OLED is degraded.Accordingly, it is possible to compensate for a decrease in luminance ofthe organic light emitting diode OLED.

The operating process of the pixel 142 according to this embodiment,except that the photodiode PD is added so that the degradation of theorganic light emitting diode OLED is compensated for, is substantiallyidentical to that of the pixel in the first embodiment shown in FIG. 2.In practice, the pixel 142 according to this embodiment can be drivenwith the driving waveforms shown in FIGS. 3 to 5.

FIG. 10 is a circuit diagram illustrating a pixel according to a fourthembodiment of the present invention. In FIG. 10, components that aresubstantially identical to those of FIG. 7 are designated by likereference numerals, and their detailed descriptions will be omitted.

Referring to FIG. 10, the pixel 142 according to this embodimentincludes a pixel circuit 220 and the organic light emitting diode OLED.

The pixel circuit 220 includes the first driver 146 for storing thecurrent data signal, and a second driver 222 for controlling an amountof the current supplied to the organic light emitting diode OLED,corresponding to the previous data signal.

The second driver 222 includes a photodiode PD coupled in parallel tothe first capacitor C1 between the first power source ELVDD and thefirst node N1. The photodiode PD controls an amount of current suppliedfrom the first power source ELVDD to the first node N1, i.e., thevoltage at the first node N1, corresponding to the brightness of theorganic light emitting diode OLED. In practice, the photodiode PDcontrols the voltage at the first node N1 so that the degradation of theorganic light emitting diode OLED can be compensated for.

FIG. 11 is a circuit diagram illustrating a pixel according to a fifthembodiment of the present invention. In FIG. 11, components that aresubstantially identical to those of FIG. 7 are designated by likereference numerals, and their detailed descriptions will be omitted.

Referring to FIG. 11, the pixel 142 according to this embodimentincludes a pixel circuit 230 and the organic light emitting diode OLED.

The pixel circuit 230 includes the first driver 146 for storing thecurrent data signal, and a second driver 232 for controlling an amountof the current supplied to the organic light emitting diode OLED,corresponding to the previous data signal.

The second driver 232 includes a third capacitor C3 coupled between thesecond node N2 and the anode electrode of the organic light emittingdiode OLED. The third capacitor C3 controls the voltage at the secondnode N2, corresponding to the voltage at the anode electrode of theorganic light emitting diode OLED. For example, the third capacitor C3controls the voltage at the second node N2 so that the degradation ofthe organic light emitting diode OLED is compensated for.

The pixel 142 according to this embodiment can be driven with any one ofthe driving waveforms shown in FIGS. 3 to 5.

The operating process of the pixel will be described in conjunction withthe driving waveform of FIG. 3. The emission control signal is suppliedto the emission control line E during the first to third periods T1 toT3, and the emission control signal is not supplied to the emissioncontrol line E during the fourth period T4. When the emission controlsignal is supplied to the emission control line E, the eighth and ninthtransistors M8 and M9 are turned off. Then, the first transistor M1 andthe organic light emitting diode OLED are electrically decoupled fromeach other, and accordingly, the organic light emitting diode OLED isset in the non-emission state during the first to third periods T1 toT3. When the ninth transistor M9 is turned off, the anode electrode ofthe organic light emitting diode OLED is set to a voltage (e.g., apredetermined voltage) Voled.

The first control signal is supplied to the first control line CL1during the first period T1 so that the sixth and seventh transistors M6and M7 are turned on. When the sixth transistor M6 is turned on, thevoltage of the initialization power source Vint is supplied to the firstnode N1. When the seventh transistor M7 is turned on, the voltage of thefirst power source ELVDD is supplied to the second node N2. In thiscase, the first transistor M1 is initialized in an on-bias state.

The second control signal is supplied to the second control line CL2during the second period T2. When the second control signal is suppliedto the second control line CL2, the third, fourth and fifth transistorsM3, M4′ and M5 are turned on.

When the fifth transistor M5 is turned on, the first transistor M1 isdiode-coupled. When the third transistor M3 is turned on, the voltage ofthe previous data signal stored in the second capacitor C2 is suppliedto the second node N2. When the fourth transistor M4′ is turned on, thevoltage Voled at the anode electrode of the organic light emitting diodeOLED is dropped to the voltage of the initialization power source Vint.In this case, the voltage at the second node N2 is dropped,corresponding to a decrement of the voltage at the anode electrode ofthe organic light emitting diode OLED, by coupling of the thirdcapacitor C3.

When the voltage of the previous data signal is supplied to the secondnode N2, the first transistor M1 is turned on. When the first transistorM1 is turned on, the voltage applied to the second node N2 is suppliedto the first node N1 via the diode-coupled first transistor M1. In thiscase, the first capacitor C1 stores a voltage corresponding to theprevious data signal, the threshold voltage of the first transistor M1and the degradation of the organic light emitting diode OLED.

For example, when the fourth transistor M4′ is turned on, the voltage atthe anode electrode of the organic light emitting diode OLED is changedas shown in Equation 2.ΔVoled=Voled−(Vint)  Equation 2

In Equation 2, Voled denotes the voltage at the anode electrode of theorganic light emitting diode OLED, applied during the first period T1.Referring to Equation 2, the voltage at the anode electrode of theorganic light emitting diode OLED during the second period T2 is droppedfrom the voltage Voled applied during the first period T1 to the voltageof the initialization power source Vint.

In this case, the variation (ΔVoled) in the voltage at the anodeelectrode of the organic light emitting diode OLED is determined by thedegradation of the organic light emitting diode OLED. In practice, asthe organic light emitting diode OLED is degraded, the resistance of theorganic light emitting diode OLED is increased. Accordingly, as theorganic light emitting diode OLED is degraded, the variation (ΔVoled) inthe voltage at the anode electrode of the organic light emitting diodeOLED is increased.

For example, the resistance of the organic light emitting diode OLED isincreased corresponding to the degradation of the organic light emittingdiode OLED. When the resistance of the organic light emitting diode OLEDis increased, the voltage Voled at the anode electrode of the organiclight emitting diode OLED, which is applied during the first period T1,is increased. Thus, as the organic light emitting diode OLED isdegraded, a decrement of the voltage at the second node N2 is increased,and accordingly, the degradation of the organic light emitting diodeOLED can be compensated for. In other words, when the voltage at thesecond node N2 is dropped, the voltage at the first node N1 is alsodropped. Accordingly, as the organic light emitting diode OLED isdegraded, an amount of the current supplied to the organic lightemitting diode OLED is increased, thereby compensating for thedegradation of the organic light emitting diode OLED.

The supply of the emission control signal to the emission control line Eis maintained during the third period T3.

The supply of the emission control signal to the emission control lineEn is stopped during the fourth period T4, so that the eighth and ninthtransistors M8 and M9 are turned on. When the eighth transistor M8 isturned on, the first power source ELVDD and the second node N2 areelectrically coupled to each other. When the ninth transistor M9 isturned on, the fourth node N4 and the anode electrode of the organiclight emitting diode OLED are electrically connected to each other.Then, the first transistor M1 controls an amount of the current flowingfrom the first power source ELVDD to the second power source ELVSS viathe organic light emitting diode OLED, corresponding to the voltageapplied to the first node N1. In this case, the organic light emittingdiode OLED generates light (e.g., light with a predetermined luminance)corresponding to an amount of current supplied thereto.

The scan signal is progressively supplied to the scan lines S1 to Snduring the fourth period T4. When the scan signal is progressivelysupplied to the scan lines S1 to Sn, the second transistor M2 includedin each pixel 142 is turned on for each horizontal line. When the secondtransistor M2 is turned on, the current data signal from a data line(any one of D1 to Dm) is supplied to the third node N3 included in eachpixel 142. In this case, the second capacitor C2 charges a voltagecorresponding to the current data signal. In practice, in embodimentsaccording to the present invention, images are displayed by repeatingthe aforementioned procedure.

FIG. 12 is a circuit diagram illustrating a pixel according to a sixthembodiment of the present invention. In FIG. 12, components that aresubstantially identical to those of FIG. 11 are designated by likereference numerals, and their detailed descriptions will be omitted.

Referring to FIG. 12, the pixel according to this embodiment includes apixel circuit 240 and the organic light emitting diode OLED.

The pixel circuit 240 includes the first driver 146 for storing thecurrent data signal, and a second driver 242 for controlling an amountof the current supplied to the organic light emitting diode OLED,corresponding to the previous data signal.

The second driver 242 includes a fourth transistor M4″ coupled betweenthe second control line CL2 and the organic light emitting diode OLED. Agate electrode of the fourth transistor M4″ is coupled to the secondcontrol line CL2. That is, the fourth transistor M4″ is diode-coupled.The fourth transistor M4″ allows the voltage at the anode electrode ofthe organic light emitting diode OLED to be dropped to approximately thevoltage of the second control signal when the second control signal issupplied to the second control line CL2.

That is, the operating process of the pixel according to thisembodiment, except that the voltage Voled at the anode electrode of theorganic light emitting diode OLED is dropped to the voltage of thesecond control signal other than that of the initialization power sourceVint, is substantially identical to that of the pixel according to thefifth embodiment shown in FIG. 11. Therefore, its detailed descriptionwill be omitted.

Although it has been described in embodiments according to the presentinvention that the transistors are shown as PMOS transistors forconvenience of illustration, the present invention is not limitedthereto. In other words, the transistors may be formed as NMOStransistors.

In embodiments of the present invention, the organic light emittingdiode OLED may generate red, green and blue light, corresponding to anamount of current supplied from the driving transistor, or may generatewhite light, corresponding to the amount of the current supplied fromthe driving transistor. In a case where the organic light emitting diodeOLED generates white light, a color image is implemented using aseparate color filter or the like.

By way of summation and review, an organic light emitting displayincludes a plurality of pixels arranged in a matrix form at crossingregions of a plurality of data lines, a plurality of scan lines and aplurality of power lines. Each pixel generally includes an organic lightemitting diode, two or more transistors including a driving transistor,and one or more capacitors.

In order to implement a 3D image, the organic light emitting displayincludes four frames during a period of 16.6 ms. A left image isdisplayed in a first frame among the four frames, and a right image isdisplayed in a third frame among the four frames. In addition, a blackimage is displayed in second and fourth frames among the four frames.

In shutter glasses, a left lens receives light during the first frame,and a right lens receives light during the third frame. In this case, auser wearing the shutter glasses recognizes, as a 3D image, an imagesupplied through the shutter glasses. The left and right lenses switchfrom either receiving light to not receiving light or from not receivinglight to receiving light while the black image is being displayed duringthe second and fourth frames, and thus it is possible to prevent theoccurrence of a crosstalk phenomenon.

However, in the related art organic light emitting display, the fourframes are included in the period of 16.6 ms, and accordingly, theorganic light emitting display is driven at a driving frequency of 240Hz. In a case where the organic light emitting display is driven at ahigh frequency, the power consumption of the organic light emittingdisplay is increased, and the stability of the organic light emittingdisplay is lowered. Further, the manufacturing cost of the organic lightemitting display is increased. Since the black image is displayed duringthe second and fourth frames, the peak current for expressing a grayscale is increased, and accordingly, the lifespan of the organic lightemitting diode is lowered.

In the pixel and the organic light emitting display using the sameaccording to embodiments of the present invention, the pixels emitlight, and concurrently (e.g., simultaneously), the data signal can becharged. Accordingly, the organic light emitting display is driven at alow frequency, thereby implementing a 3D image. Further, the drivingtransistor included in each pixel is initialized in an on-bias statebefore the data signal is supplied, thereby displaying a uniform image.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims and their equivalents.

What is claimed is:
 1. A pixel comprising: an organic light emittingdiode; a second driver configured to control an amount of currentsupplied from a first power source to the organic light emitting diode,corresponding to a previous data signal; and a first driver configuredto store a current data signal supplied from a data line and to supplythe previous data signal to the second driver, wherein the second drivercomprises: a sixth transistor coupled between an initialization powersource and a first node coupled to a gate electrode of a firsttransistor, the sixth transistor being configured to turn on when afirst control signal is supplied; and a seventh transistor coupledbetween the first power source and a second node commonly coupled to thefirst and second drivers, the seventh transistor being configured toturn on when the first control signal is supplied.
 2. The pixel of claim1, wherein the initialization power source has a voltage lower than thatof a data signal supplied to the data line.
 3. The pixel of claim 1,wherein the first driver comprises: a second transistor coupled betweenthe data line and a third node, the second transistor being configuredto turn on when a scan signal is supplied to a scan line; a thirdtransistor coupled between the third and second nodes, the thirdtransistor being configured to turn on when a second control signal issupplied; and a second capacitor coupled between the third node and theinitialization power source.
 4. The pixel of claim 3, wherein the thirdand sixth transistors have turn-on periods not overlapped with eachother.
 5. The pixel of claim 3, wherein the second transistor has aturn-on period not overlapped with those of the third and sixthtransistors.
 6. The pixel of claim 1, wherein the second drivercomprises: an eighth transistor coupled between the first power sourceand the second node, the second node being coupled to a first electrodeof the first transistor, the eighth transistor being configured to turnoff when an emission control signal is supplied and to turn onotherwise; a fifth transistor coupled between the first node and asecond electrode of the first transistor, the fifth transistor beingconfigured to turn on when a second control signal is supplied; a ninthtransistor coupled between the second electrode of the first transistorand an anode electrode of the organic light emitting diode, the ninthtransistor being configured to turn off when the emission control signalis supplied and to turn on otherwise; and a first capacitor coupledbetween the first node and the first power source.
 7. The pixel of claim6, wherein the eighth transistor has a turn-on period not overlappedwith those of the fifth and sixth transistors.
 8. The pixel of claim 6,wherein the fifth and sixth transistors have turn-on periods notoverlapped with each other.
 9. The pixel of claim 6, wherein the seconddriver further comprises a fourth transistor coupled between the anodeelectrode of the organic light emitting diode and the initializationpower source, the fourth transistor being configured to turn on when thefirst control signal is supplied.
 10. The pixel of claim 6, wherein thesecond driver further comprises a fourth transistor coupled between theanode electrode of the organic light emitting diode and theinitialization power source, the fourth transistor being configured toturn on when the second control signal is supplied.
 11. The pixel ofclaim 6, wherein the second driver further comprises a fourth transistorcoupled between the anode electrode of the organic light emitting diodeand a second control line to which the second control signal issupplied, the fourth transistor having a gate electrode coupled to thesecond control line.
 12. The pixel of claim 6, wherein the second driverfurther comprises a photodiode coupled in parallel to the firstcapacitor between the first node and the first power source.
 13. Thepixel of claim 12, wherein the photodiode is configured to control anincrement of a voltage at the first node, corresponding to a luminanceof the organic light emitting diode.
 14. The pixel of claim 12, whereinthe photodiode is configured to control an increment of a voltage at thefirst node, in proportion to a luminance of the organic light emittingdiode.
 15. The pixel of claim 6, wherein the second driver furthercomprises a third capacitor coupled between the anode electrode of theorganic light emitting diode and the second node.
 16. An organic lightemitting display comprising: a control driver configured to supply afirst control signal to a first control line during a first period inone frame, and to supply a second control signal to a second controlline during a second period in the one frame; a scan driver configuredto supply an emission control signal to an emission control line duringthe first period, the second period, and a third period in the oneframe, and to progressively supply a scan signal to scan lines during afourth period in the one frame; a data driver configured to supply adata signal to data lines, in synchronization with the scan signal,during the fourth period in the one frame; and pixels positioned in anarea defined by the scan lines and the data lines, the pixels beingconfigured to store a current data signal during a period in which thepixels emit light, corresponding to a previous data signal, wherein thethird period is different from the first and the second period.
 17. Theorganic light emitting display of claim 16, wherein the previous datasignal is the data signal supplied in a previous frame, and the currentdata signal is the data signal supplied in a current frame.
 18. Theorganic light emitting display of claim 16, wherein the scan driver isconfigured to supply the scan signal concurrently to the scan linesduring the third period.
 19. The organic light emitting display of claim16, wherein the data driver is configured to supply a reset voltage tothe data lines during the third period.
 20. The organic light emittingdisplay of claim 19, wherein the reset voltage is set to a voltage in avoltage range of the data signal.
 21. The organic light emitting displayof claim 16, wherein each of the pixels is configured to control anamount of current flowing from a first power source to a second powersource via an organic light emitting diode, corresponding to theprevious data signal.
 22. The organic light emitting display of claim21, wherein the first power source is set to a first voltage during thefourth period, and is set to a second voltage different from the firstvoltage during the first to third periods.
 23. The organic lightemitting display of claim 22, wherein the second voltage is a voltagelower than the first voltage.
 24. The organic light emitting display ofclaim 16, wherein each of the pixels comprises: an organic lightemitting diode; a second driver configured according to an amount ofcurrent supplied from a first power source to the organic light emittingdiode, corresponding to the previous data signal; and a first driverconfigured to store the current data signal, and to supply the previousdata signal to the second driver.
 25. The organic light emitting displayof claim 24, wherein the first driver comprises: a second transistorcoupled between a corresponding one of the data lines and a third node,the second transistor being configured to turn on when the scan signalis supplied to a corresponding one of the scan lines; a third transistorcoupled between the third node and a second node commonly coupled to thefirst and second drivers, the third transistor being configured to turnon when the second control signal is supplied; and a second capacitorcoupled between the third node and an initialization power source. 26.The organic light emitting display of claim 24, wherein the seconddriver comprises: a first transistor having a first electrode coupled tothe first power source via a second node commonly coupled to the firstand second drivers, the first transistor having a gate electrode coupledto a first node; a fifth transistor coupled between a second electrodeof the first transistor and the first node, the fifth transistor beingconfigured to turn on when the second control signal is supplied; asixth transistor coupled between the first node and an initializationpower source, the sixth transistor being configured to turn on when thefirst control signal is supplied; a seventh transistor coupled betweenthe second node and the first power source, the seventh transistor beingconfigured to turn on when the first control signal is supplied; aneighth transistor coupled between the second node and the first powersource, the eighth transistor being configured to turn off when theemission control signal is supplied and to turn on otherwise; and aninth transistor coupled between the second electrode of the firsttransistor and an anode electrode of the organic light emitting diode,the ninth transistor being configured to turn off when the emissioncontrol signal is supplied and to turn on otherwise.
 27. The organiclight emitting display of claim 26, wherein the initialization powersource is set to a voltage lower than the data signal.
 28. The organiclight emitting display of claim 26, wherein the second driver furtherincludes a fourth transistor coupled between the anode electrode of theorganic light emitting diode and the initialization power source, thefourth transistor being configured to turn on when the first controlsignal is supplied.
 29. The organic light emitting display of claim 26,wherein the second driver further comprises a fourth transistor coupledbetween the anode electrode of the organic light emitting diode and theinitialization power source, the fourth transistor being configured toturn on when the second control signal is supplied.
 30. The organiclight emitting display of claim 26, wherein the second driver furthercomprises a fourth transistor positioned between the anode electrode ofthe organic light emitting diode and the second control line, the fourthtransistor having a gate electrode coupled to the second control line.31. The organic light emitting display of claim 26, wherein the seconddriver further comprises a photodiode coupled in parallel with a firstcapacitor between the first node and the first power source.
 32. Theorganic light emitting display of claim 31, wherein the photodiode isconfigured to control an increment of a voltage at the first node,corresponding to a luminance of the organic light emitting diode. 33.The organic light emitting display of claim 31, wherein the photodiodeis configured to control an increment of a voltage at the first node, inproportion to a luminance of the organic light emitting diode.
 34. Theorganic light emitting display of claim 26, wherein the second driverfurther comprises a third capacitor coupled between the anode electrodeof the organic light emitting diode and the second node.
 35. A pixelcomprising: an organic light emitting diode; a second driver configuredto control an amount of current supplied from a first power source tothe organic light emitting diode, corresponding to a previous datasignal; and a first driver configured to store a current data signalsupplied from a data line and to supply the previous data signal to thesecond driver, wherein the second driver comprises: a fourth transistorcoupled between an anode electrode of the organic light emitting diodeand an initialization power source, the fourth transistor beingconfigured to turn on when a second control signal is supplied; aseventh transistor coupled between the first power source and a secondnode commonly coupled to the first and second drivers, the seventhtransistor being configured to turn on when a first control signal issupplied; and a second capacitor coupled between the anode electrode ofthe organic light emitting diode and the second node.
 36. The pixel ofclaim 35, wherein the first driver comprises: a second transistorcoupled between the data line and a third node, the second transistorbeing configured to turn on when a scan signal is supplied to a scanline; a third transistor coupled between the third and second nodes, thethird transistor being configured to turn on when the second controlsignal is supplied; and a third capacitor coupled between the third nodeand the initialization power source.
 37. The pixel of claim 35, whereinthe second driver comprises: a fifth transistor coupled between a firstnode coupled to a gate electrode of a first transistor and a secondelectrode of the first transistor, the fifth transistor being configuredto turn on when the second control signal is supplied; a sixthtransistor coupled between the initialization power source and the firstnode, the sixth transistor being configured to turn on when the firstcontrol signal is supplied; an eighth transistor coupled between thefirst power source and the second node, the second node being coupled toa first electrode of the first transistor, the eighth transistor beingconfigured to turn off when an emission control signal is supplied andto turn on otherwise; a ninth transistor coupled between the secondelectrode of the first transistor and the anode electrode of the organiclight emitting diode, the ninth transistor being configured to turn offwhen the emission control signal is supplied and to turn on otherwise;and a first capacitor coupled between the first node and the first powersource.
 38. The pixel of claim 37, wherein the eighth transistor has aturn-on period not overlapped with those of the fifth and sixthtransistors.
 39. The pixel of claim 37, wherein the fifth and sixthtransistors have turn-on periods not overlapped with each other.